Table 4.

Values of MAE on the test set obtained for RF, ANN ensemble and quadratic regression with interactions (RSM) models. The smallest errors are reported in bold, and the reduction (in percentage) of the MAE obtained for the best model vs. the RSM approach is reported as well (Δ).

Name	RF	ANN ensemble	RSM	Δ [%]
$y1$	3.624	3.842	4.553	20.40
$y2$	1.874	1.974	2.449	23.48
$y3$	1.921	1.697	2.376	28.56